1. Field of the Invention
The present invention relates to a lens barrel and an image pickup device, and in particular relates to a lens barrel that includes a bending optical system, an image pickup device, and a lens barrel inspecting method and a lens barrel manufacturing method.
2. Background Information
Digital cameras which make use of image sensors such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) sensor to convert an optical image into an electrical signal, and to record by digitizing the electrical signal, have become very popular in recent years.
In this kind of digital camera, there is a need for a smaller size body in order to improve portability. To this end, there is a need for reduced size in an image pickup apparatus equipped with a lens barrel and image sensors, which is believed to contribute greatly to reducing the size of the housing. In these efforts to reduce the size of an image pickup apparatus, what is known as a bending optical system has been proposed, in which the apparatus is reduced in size by bending the zoom lens system at some point along the optical path, without changing the optical length (for example, refer to Patent Documents 1 and 2).    Patent Document 1: Japanese Patent Laid-Open Publication No. 2005-121974    Patent Document 2: Japanese Patent Laid-Open Publication No. 2005-10279